


Experimentation

by ThatMasterOnline



Category: Shingeki no Kyojin | Attack on Titan
Genre: M/M
Language: English
Status: Completed
Published: 2020-10-10
Updated: 2020-10-10
Packaged: 2021-03-07 19:07:00
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,806
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26932612
Author URL: https://archiveofourown.org/users/ThatMasterOnline/pseuds/ThatMasterOnline
Summary: Eren and Armin experiment with eachother's bodies to find out what they like. Erwin asks for a demonstration so he can find out what they like, too. Contains voyeurism, daddy kink, ear licking, sexual cuddling, and a blindfold. It's shameless smut, I don't know what to tell you.
Relationships: Armin Arlert/Eren Yeager, Armin Arlert/Erwin Smith/Eren Yeager
Kudos: 13





	Experimentation

**Author's Note:**

> The Attack on Titan canon past season 1 is bullshit, so anything AoT related will be Fuck You Everyone Lives And Sometimes They Have Kinky Sex. This is my canon now.

Erwin loved having Eren and Armin. The three of them had a perfectly balanced relationship that suited them. It was quiet, it was domestic, it was loud, when Eren felt like arguing, it was intellectually stimulating, when Armin felt like going on about his latest theories, and it was most certainly a delight in the bedroom.

Erwin would never stop thanking his lucky stars that he had not one, but two sexual partners who liked calling him Daddy, and dominating the two of them was an absolute delight, but Eren and Armin also had their own relationship. One that almost felt more exploratory in nature. That made sense; Eren, as the newest of their trio, was still a little uncertain about opening up to Erwin about his desires, so he often explored with Armin, and then Armin would tell Erwin, with Eren's permission. It worked. Besides, Erwin could always tell when they were exploring eachothers' bodies in his absence; Eren stopped being able to look him in the eye. This wasn't unusual, but what made this particular day interesting was that Armin was also skittish, which was new.

Clearly it was time for an intervention.

"My angel, my kitten," Erwin said, looking at his two lovers. Armin was curled up against Eren who was curled up against Erwin on the couch. Both boys turned to look at him.

"I'm thinking we could all use a little stress relief. Shall we?" He waved a hand in the direction of the bedroom to show what he was getting at. They nodded, and once they entered the bedroom Erwin took control.

"Now, my darlings, lie down on the bed. Get comfortable." Eren and Armin did as told, laying next to each other, then looked to him for the next step. Erwin knelt on the bed, using his hands to gently rub both their bodies, watching as they relaxed into the touch.

"Now, I may have lied a little bit. When I said we all needed to relax...what I meant was you two needed to relax." Both stiffened, but Erwin shushed them.

"Hush now, none of that. I said we're relaxing and I meant that. You're not in trouble...in fact, nothing you say or do will get you into trouble for the rest of the night." He smiled as they both stared at him wide-eyed, casting a quick glance at each other and then back to him.

"Consider it a treat for being so good. I want you to just relax. We're making tonight all about you two." Erwin stroked Eren's cheeks, then Armin's then leaned down and began gently kiss them one at a time.

"But...Daddy…" Eren began, tentatively, "I don't understand...What about you?" Erwin hummed.

"You're right, I might not get any pleasure tonight. I consider this an investment that will pay dividends in the weeks and months to come. I can get my pleasure then. Now, you two need to relax. So just lie still and let me get you both all nice and warmed up." Erwin took his time, stroking and pleasuring them until they were warm and hard, and then he kissed them.

"You two like each other, don't you?" Both boys looked at each other, then nodded. Erwin gave each of them a deep kiss as a reward.

"I know you like to experiment with each other when I'm not around and that's okay. I want you two to feel like you're connected by more than just your relationship to me. So you explore, and you touch each other…" Erwin paused, considering his next words carefully. He could easily ruin all of his delicately-built relaxation if this went south. He took a breath.

"...Sometimes, Eren…" he began, "When you discover something you like...You get nervous. You have a hard time looking me in the eye. You want to tell me about the thing you like, but you still don't know how. Did you know that?" Eren flushed, looking away.

"...Armin always offers to talk to you about it instead," he said, and Erwin kissed him.

"Good boy. Yes, Armin tells me about the things you like. We're trying to build up your confidence so you'll do it yourself someday. And you've been doing it again, so I know you and Armin found something you like. But something's different this time around. Can either of you guess what it is?" Eren shook his head, but Armin put his hand up tentatively.

"...I'm doing it too," he said, and Erwin kissed him.

"My beautiful angel. Yes, that's exactly right. So here's what I want." He kissed them, running his hands up both their bodies, stroking and trying to massage away the lingering tension. "I want you both to get nice and relaxed, and when you're ready, I'd like you to show me what you like. Can you do that? Armin nodded, and Eren did the same after looking to Armin for assurance. Erwin pulled back.

"Alright. I'll do what I can to help relax you at first, but then I'll just sit back and let you take control." Eren and Armin looked deep into eachothers' eyes, and then they kissed, soft and sweet and tentative.

"Eren," Armin whispered, "Can you lay on top of me? My arm is starting to ache." They kissed briefly, changing positions so Armin was on his back, with Eren leaning over him as they kissed. Eren began to run his hands over Armin's body, and Armin closed his eyes.

"I'm a little nervous…" Armin whispered, and Eren kissed his cheek, feeling Erwin rub his back gently as he did so.

"Daddy just wants to make us feel good, right? He's just asking us to teach him how." He leaned down and kissed Armin again. 

"Don't think about Daddy right now, though, think about me. All this talk of the thing I like...it's making me think about it. I...really want it, Armin." He kissed him again.

"You're so beautiful, Armin...and you do it really well...I want you to make me feel good, Armin…" They kissed again, but it was deeper this time, more intense, Erwin noting that Armin was finally starting to relax. He slid off the bed as quietly as he could, but still Armin looked over. Eren kissed his cheek, drawing his attention back.

"It's okay, Armin," he whispered, "I've got you." Erwin noticed that with that one sentence Armin's tension began to melt away, and he kissed Eren deeply, forgetting about Erwin again.

"Eren…"

"Shh, I've got you. It's okay, Armin, I'm here." They kept kissing, but Armin's nerves drew him back again.

"Eren…" he whispered, "Could you blindfold me? That might help with the nerves a bit…" Eren kissed him.

"Of course." Eren climbed off the bed, stroking Armin's cheek soothingly, and pulled the blindfold from its usual place. He climbed back on the bed and gently placed it over Armin's eyes.

"Better?" Eren asked in a whisper, and Armin nodded.

"Much." Eren went behind Armin, wrapping his arms around him, and Armin relaxed immediately.

"Eren…"

"You feel so safe and warm in my arms, don't you?" Eren asked, and Armin moaned.

"I've got you, Armin. I'll keep you nice and safe, you won't have to worry about a thing, just let me take care of you…" Armin hummed, starting to rock his hips slightly, but Eren was relentless.

"I've got you, Armin. Just let me take care of everything. All you have to do is feel the way I make you feel, safe, and warm, and happy, and protected...My arms around you makes you feel so protected, doesn't it?" Armin moaned again, helped along by Eren reaching into Armin's shorts and pulling out his member.

"You're doing so good, Armin," he whispered, watching as Armin shuddered. His head fell back, and Eren took the opportunity to mouth at his neck.

"Ohhh…"

"Come on, Armin, it's okay. You're with me, you're safe. You can relax with me, Armin, it's alright." Armin began to gasp and tremble, and a few more seconds of Eren's gentle assurances that he was safe had him coming into Eren's hand.

"There...you did so good, Armin...Just breathe, okay, I've got you." Armin came down from his high slowly, and as he did he realized that Erwin was there.

"...You have me, right, Eren?"

"Yes, Armin, I've got you. Everything's okay." Erwin wondered at Armin's unusual shyness, but decided he would question it when they weren't already being so vulnerable for him.

"You did so good, Armin, you were wonderful." Armin took a few steadying breaths, then took his blindfold off, sitting up.

"How are you?" Eren asked, sitting up and wrapping his arms around him.

"...A little tired," Armin finally said, "I'll be looking forward to sleeping after this. But right now…" He turned and kissed Eren.

"I get to take care of you and make you feel good, too." Eren swallowed.

"I've been waiting." Armin leaned forward, pinning Eren down.

"...Do you need the blindfold?" Armin asked gently.

"...No, I'll be alright. You do such a good job making me feel so good I can't think about anything else."

"Flatterer," Armin said, and kissed him. The kissing moved to Eren's cheek, his neck. A quiet pause, and then Armin opened his mouth and licked Eren's ear from bottom to top. Eren sighed. 

No words were spoken, Armin licked and kissed and sucked and mouthed at Eren's ears, occasionally switching from one to the other, and Eren was sighing his pleasure constantly. Eren reached for himself as Armin continued.

"My arm is getting tired," he joked breathlessly, and Armin laughed. Silence fell again as Armin worked Eren's ears with single-minded focus, using his lips, his tongue, sometimes teeth but mostly not. Eren began to squirm, his end fast approaching, and Armin kept up the pace until he burst, coming hard on his clothed stomach. He came down from his high, and Armin's attention to his ears had gentled, but not fully stopped. Erwin waited until both of them were fully relaxed before he spoke.

"Thank you," he said first, because his two lovers had revealed a lot of themselves, and Erwin had to respect that precious gift. He wiped the sheets with a cloth, then nudged Eren to pull off his shirt and toss it in the laundry.

"You two did so well," he said, and Armin flushed. Erwin crawled back into bed. Eren snuggled up to him, and Armin snuggled up to Eren - and oh, that made so much more sense now.

"I'll have a lot to think about tonight," Erwin said, "but you two just need to sleep." Armin hummed and didn't object at all, closing his eyes. Eren turned to kiss Erwin.

"Love you, Daddy."

"Love you more, kitten."


End file.
